Definitions for bete noire

Even more regrettable, as far as Dame Edna is concerned, is the presence of her old bete noire, the extravagantly disgusting Sir Les Patterson., Daily Telegraph

Never an exceptional student, Andrews somehow managed to navigate the academy's rigorous courses with satisfactory grades, though all forms of mathematics were agonizing to him, remaining what he called his "bete noire" throughout life.Charles Gallenkamp, Dragon Hunter: Roy Chapman Andrews and the Central Asiatic Expeditions